Keep CLAUDE.md in sync with this file — it's a copy used by Claude Code.

# Windows (MinGW) — Debug
cmake -B build_mingw -G "MinGW Makefiles" -DCMAKE_BUILD_TYPE=Debug
cmake --build build_mingw

# Windows — deploy Qt DLLs for distribution
cmake --build build_mingw --target deploy

# One-click release packaging (build + deploy + strip credentials + zip)
# Requires bash: Git Bash, WSL, or MSYS2
bash package.sh v1.0.3

# Linux (native)
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

# Windows → Linux cross-compile (Zig) — NOTE: cmake/toolchains/linux-x64.cmake
# is NOT in the repo; you must supply it externally.
export ZIG_PATH=/path/to/zig/zig.exe
cmake -B build_linux -G "MinGW Makefiles" \
      -DCMAKE_TOOLCHAIN_FILE=cmake/toolchains/linux-x64.cmake \
      -DZIG_PATH="$ZIG_PATH" -DCMAKE_BUILD_TYPE=Release
cmake --build build_linux

• C++17, Qt 6 (Core, Widgets, Mqtt), CMake ≥ 3.10
• Binary: DjiCloudApi.exe (Windows), main (Linux cross-compile)
• cmake/toolchains/linux-x64.cmake is not committed — the Zig cross-compile path needs it externally
• CMake copies config/topic_mappings.json → build dir on every build
• CMake copies src/resources/config.json → build dir config.json only on first build (preserves credentials)
• package.sh replaces config.json with deploy/config.example.json to strip credentials before zipping
• Build output goes to build_mingw/; deploy/ holds pre-built distribution artifacts (exe is committed, DLLs are gitignored)
• No lint, typecheck, or test commands exist in this project

At runtime (see src/main.cpp):

1. <exe_dir>/config/config.json (primary — config/ subdir is auto-created on startup)
2. ./config.json (CWD-relative fallback for backward compat)

The CMake template src/resources/config.json is copied to the build root. At runtime the app may move/create it inside config/. When editing config, check both locations.

Three-layer, single-threaded — Qt signals/slots for async I/O:

UI Layer      src/ui/     — MainWindow, DeviceTreeWidget, OsdPanel, TopicParsePanel,
                            RawJsonPanel, PublishPanel, ConfigDialog, TopicListWidget,
                            DockControlPanel, FlightControlPanel, MaintenancePanel
Core Layer    src/core/   — DeviceManager (central dispatcher), ConfigStore, TopicManager,
                            TopicMapping, DeviceInfo/OsdData structs,
                            DockCommand/DockCommandExecutor (command system)
MQTT Layer    src/mqtt/   — MqttClientManager (QMqttClient wrapper, exponential backoff reconnect)

Data flow: MQTT message → MqttClientManager::messageReceived → DeviceManager::parseAndRoute() → TopicManager matches topic to device SN → parses DJI-format JSON {"tid":..., "data":...} → caches OSD, emits deviceOsdUpdated(sn, rawJson) → UI panels reactively update.

Thread model: Everything runs on the Qt main thread. QMqttClient is async — no worker threads.

UI language: All labels, field names, enum values are Chinese (UTF-8). Compiler flags enforce UTF-8 encoding: /utf-8 (MSVC), -fexec-charset=UTF-8 (GCC/MinGW).

DeviceInfo has parentSn — dock devices are top-level, aircraft can be children of a dock (isChild()). Tree renders as two-level hierarchy. Child aircraft are auto-discovered from dock OSD messages (DeviceManager::checkAndAddChildAircraft).

DJI sends OSD fields split across multiple MQTT messages. DeviceManager uses mMergedOsdData to merge fields incrementally — the latest value for each field key wins. The UI sees the merged result.

• Offline timeout: 5 seconds (OFFLINE_TIMEOUT_MS=5000) — no message received → device marked offline
• JSON history: 500 entries per device per topic (MAX_JSON_HISTORY=500)

DeviceManager::switchToProfile() disconnects → clears all runtime state (devices, OSD caches, JSON history, topics) → loads new profile → reconnects if was connected. ConfigStore auto-saves on profile switch.

Topics stored with {sn} placeholder in config; TopicManager resolves at runtime. Each device has its own topic list. Topics individually enable/disable. Disabled topics tracked separately and automatically unsubscribed.

Common prefixes (replace {sn} with device serial):

• thing/product/{sn}/osd — telemetry/OSD data
• thing/product/{sn}/state — device state
• thing/product/{sn}/services — command requests (publish)
• thing/product/{sn}/services_reply — command responses (subscribe)
• sys/product/{sn}/status — system status

• config.json — Multi-profile MQTT config + devices. Auto-generated on first run from src/resources/config.json template. Contains credentials — never commit (gitignored).
• config/topic_mappings.json — JSON field → Chinese translations. Topic keys use {sn} placeholder and optional dock//aircraft/ prefix. Copied to build dir on every build.
• deploy/config.example.json — Template with placeholder values, used during packaging.
• deploy/DjiCloudApi.exe + deploy/*.dll — Pre-built distribution binaries. DLLs are gitignored; the exe is committed.

• RawJsonPanel is header-only (RawJsonPanel.h ~276 lines, no .cpp). Packet capture writes to <exe_dir>/captures/.
• FlowLayout.h is a standalone Qt layout helper, no .cpp.
• DockControlDialog / FlightControlDialog / MaintenanceDialog are thin dialog wrappers that embed their respective *Panel widget.
• Maintenance panel features are mostly "coming soon" stubs.

This project has no automated test suite. All verification is manual.